Correlation between polymorphisms of surfactant protein A1 rs1059047 and rs1136450 and respiratory distress syndrome in Mongolian premature infants

Abstract

Objective To study the correlation between polymorphisms of surfactant protein A1 rs1059047 and rs1136450 and respiratory distress syndrome (RDS) in Mongolian premature infants in Inner Mongolia. Methods Totally 50 Mongolian RDS premature infants in our ward were recruited as the case group (33 males and 17 females), and another 50 Mongolian non-RDS premature infants with same ethnicity, same sex and gestational age were served as the control group (29 males and 21 females). Single nucleotide polymorphisms of SP-A1 rs1059047 and, rs1136450 and allele haploids (6A, 6A2, and 6A3) were detected by polymerase chain reaction-single strand conformation polymorphism gene detection technology and were compared between the case and control groups. Results Three genotypes, CC, TT, CT were detected in the case and control groups at rs1059047, all of which were mainly TT genotype. There was no significant difference in genotype frequency between the two groups (χ2=1.429, P > 0. 05). Two genotypes, CG and GG, were detected in the case and control groups at rs1136450, and CG was the dominant genotype. There was no significant difference in genotype frequency between the two groups (χ2= 1.624, P>0.05). The distribution frequency of SP-A1 allele haploids (6A, 6A2, 6A3) in the case group was 36%, 68% and 42%, respectively, and 62%, 46% and 50% in the control group, respectively. There was no significant difference in the frequency of allele haploid 6A3 between the two groups (χ2=0.502, P>0.05); but there was a significantly difference in the frequency of allele haploids (6A, 6A2) between the two groups (χ2=6.763, 4.937, P<0.05). Conclusions The alleles and allele frequency of SP-A1 (rs1059047, rs1136450) were not associated with RDS in Mongolian premature infants. However, SP-A1 allele haploid 6A2 is the susceptible gene for RDS in Mongolian premature infants, and haploid 6A is the protective gene. Key words: Surfactant protein-A1; Respiratory distress syndrome; Mongolian premature infants; Gene variants